126. When bundle conductors are used in place of single conduct or s, the effective inductance and capacitance will respectively

1. 1. increase and decrease

   
   
   

   2. decrease and increase

   
   
   

   3. decrease and remain unaffected

   
   
   

   4. remain unaffected and increase

   
   
   

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1. View Hint View Answer Discuss in Forum

   Building increase self GMD-D, and hence effective inductance reduces and capacitance increases.

   Correct Option: B

   Building increase self GMD-D, and hence effective inductance reduces and capacitance increases.

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127. A medium line with parameters A, B, C, D is extended by connecting a short line of impedance Z in series. The over all ABCD par ameters of the series combination will be

1. 1. A, AZ, C + D/Z, D

   
   
   

   2. A, AZ + B, C, CZ + D

   
   
   

   3. A + BZ, B, C + DZ, D

   
   
   

   4. AZ, B, C/Z, D

   
   
   

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1. View Hint View Answer Discuss in Forum

   	A		B		=		A1		B1
   	C		D				C1		D1

   
   For a short line, A = 1, B = Z, C = 0, D = 1
   ∴ Resultant parameters are given by
   

   	AT		BT		=		A		B
   	CT		DT				C		D

   
   

   	1		Z		=		A		AZ + B
   	0		1				C		CZ + D

   Correct Option: B

   	A		B		=		A1		B1
   	C		D				C1		D1

   
   For a short line, A = 1, B = Z, C = 0, D = 1
   ∴ Resultant parameters are given by
   

   	AT		BT		=		A		B
   	CT		DT				C		D

   
   

   	1		Z		=		A		AZ + B
   	0		1				C		CZ + D

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128. A single phase transmisson line of impedance j 0.8 ohm supplies a resistive load of 500 A at 300 V. The sending end power factor is

1. 1. unity

   
   
   

   2. 0.8 lagging

   
   
   

   3. 0.8 leading

   
   
   

   4. 0.6 lagging

   
   
   

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1. View Hint View Answer Discuss in Forum

   V_S = V_r + IZ_s
   = 300 + j 0.8 × [500 × 0.8 – 500 × 0.6]
   = 300 + j 0.8 [400 – j 300]
   = 300 + j 320 + 240 = 540 + j 320
   

   =	320	= 0.6 lag
   	500

   Correct Option: D

   V_S = V_r + IZ_s
   = 300 + j 0.8 × [500 × 0.8 – 500 × 0.6]
   = 300 + j 0.8 [400 – j 300]
   = 300 + j 320 + 240 = 540 + j 320
   

   =	320	= 0.6 lag
   	500

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129. Which one of the following statements is not correct for the use of bundled conduct or sin transmission lines?

1. 1. Control of voltage gradient

   
   
   

   2. Reduction in corona loss

   
   
   

   3. Reduction in radio interference

   
   
   

   4. Increase in interference with communication lines

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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130. For equilateral spacing of conductors of an untrasposed 3-phase line, we have

1. 1. bal anced receiving end voltage and no communication interference

   
   
   

   2. unbalanced receiving end volt age and no communication interference

   
   
   

   3. balanced receiving end voltage and communication interference

   
   
   

   4. unbal anced receiving end voltage and communication interference.

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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